[Devel] Re: seems to be a flaw in cfq

[Jens Axboe]

On Thu, Dec 21 2006, Vasily Tarasov wrote:
> Hello, Jens,
> 
> Sorry for late answer.
> The situation is the following:
> 
> direct seqread
> (2.6.18) - reproducable
> (2.6.20-rc1) - reproducable
> (2.6.20-rc1 + your fix) - not reproducable
> 
> buffered randread
> (2.6.18) - reproducable
> (2.6.20-rc1) - not reproducable
> (2.6.20-rc1 + your fix) - not reproducable
> 
> So the conclusion: problem with "direct seqread" is fixed by your patch
> (thanks!) and
> the problem with "buffered randread" was fixed in 2.6.19/2.6.20.

Perfect, explains why I didn't see much badness with buffered io on
2.6.20-rc1'ish. Thanks for retesting and the initial report, the fix I
sent you is going upstream (sitting in the 'for-linus' branch awaiting a
pull) for 2.6.20-rc2.

-- 
Jens Axboe